Electrical generation is a persistent challenge in downhole drilling environments. Transmission of power from the surface is often not practicable. Accordingly, downhole power generation devices such as mud motors are often used. While such devices often be incorporated at the end of a drill string, mud motors are generally too large both in terms of size and power output for relay devices distributed along the drill string. Accordingly, there is a need for power generation devices that are capable of installation and power generation along a drill string.